Process for forming an improved fiber tow by applying false twist to the tow

ABSTRACT

The method of this invention comprises combining ends of yarn through means to impart false twist and means to form the yarn into a tow so that ends which fail to run freely break, rather than disrupt the orderly lay pattern of the tow. The apparatus of this invention is the improvement comprising means to impart false twist to a tow of combined ends in a combination comprising (a) means to hold the ends of the yarn, (b) means to combine ends of yarn, (c) at least one means to linearly move a tow of combined ends and (d) means to collect the tow.

Brandi et a1.

14 1 Dec. 24, 1974 [75] Inventors: Adolph John Brandi; James Vincent Muthig, both of Columbia, SC.

[73] Assignee: Allied Chemical Corporation, New

York, NY.

22 Filed: Sept. 7, 1973 21 Appl. No.: 395,101

[52] US. Cl. 57/156, 57/51 [51] Int. CL... D0lh 5/00 [58] Field of Search... 57/1 R, 13, 14,34 R, 34 HS, 57/515l.6, 77.3,1, 77.45, 90, 156,157 R,

2,674,013 4/1954 Place 57/77.3 UX 2,775,858 1/1957 Kruse 57/51 2,886,939 5/1959 Wilks 57/51 3,099,907 8/1963 Masure1etal..... 57/51 X 3,456,431 7/1969 Fleissner 57/77.3 X 3,685,102 8/1972 Johns 19/157 X Primary ExaminerDonald Watkins Attorney, Agent, or FirmRichard A. Anderson [57] ABSTRACT The method of this invention comprises combining ends of yarn through means to impart false twist and means to form the yarn into a tow so that ends which fail to run freely break, rather than disrupt the orderly lay pattern of the tow. The apparatus of this invention is the improvement comprising means to impart false twist to a tow of combined ends in a combination comprising (a) means to hold the ends of the yarn, (b) means to combine ends of yarn, (c) at least one means to linearly move a tow of combined ends and ((1) means to collect the tow.

[56] References Cited UNITED STATES PATENTS 1,724,200 8/1929 Hubbard 57/77.3 X 1,922,949 8/1933 Harris 57/51 X 1,926,288 9/1933 Koch 57/51 X PROCESS FOR FORMING AN IMPROVED FIBER TOW BY APPLYING FALSE TWIST TO THE TOW BACKGROUND OF THE INVENTION Oftentimes a creel load of many packages of continuous running lengths of undrawn multifilament yarn is combined into a tow which is drawn, chopped, and spun into yarn which can be used in tufted or woven dyed fabrics such as carpets. Thus, it is often necessary to combine multiple continuous running lengths of ends of undrawn multifilament yarn from a number of individual packages into a single tow containing many hundreds of ends. The tow is then drawn on a tow stretcher to orient the molecular structure of the yarn and develop the desired properties.

In the tow-forming operation, yarn is withdrawn from the creel containing the individual packages combined into a single tow by means of suitable guides and carried over a pair of feed roll assemblies to a piddlerstand, where it is layered into a tow can. In order to produce an acceptable tow in this manner, the many individual ends must be taken up at a uniform rate, so that the fibers in the resulting tow are parallel and in phase with each other, i.e., they lay correctly A major problem arises when one of the various ends becomes trapped or entangled or for any other reason fails to feed freely. This condition is described as a tight end. Since the supply yarn is undrawn, the tight end stretches to several times its length before breaking. At the same time, the other ends become slack. This discontinuity in the tow creates several difficulties in subsequent processing.

1. When the uneven tow is fed into the tow can, it disrupts the orderly pattern which normally results from uniform laying of the tow. This causes tangles and poor withdrawal from the can when the tow is withdrawn to be stretched.

2. When the non-uniform tow goes through the stretcher, i.e., is drawn, it usually forms a knot and breaks out in the stretcher.

3. If the non-uniformity does get through the stretcher, experience shows that it is almost always only partially drawn. This results in dye non-uniformities in the finished product.

These problems are extremely detrimental to the product quality as well as costly in operating labor. To eliminate them, the usual solution has been to install electrically-operated tight-end cutters at each position in the creel. Since many hundreds of ends are involved, and since tight-end cutters are apt to cost as must as per position installed, this is obviously a costly solution. It is not feasible to cut the tight ends manually, since the damage is already done by the time the operator finds the proper end. An end is a single multifilament yarn or a group of filaments usually done up or wound up on a single package.

SUMMARY OF THE INVENTION The method of this invention is an improvement in combining multiple continuous running lengths of ends of undrawn multifilament yam into a tow. The improvement comprises combining the ends by passing the ends through means that impart false twist to the combined ends. ln this way the tow of combined ends maintains uniform tension between ends by breaking any tight ends, i.e., maintains a good lay. The apparatus of this invention is an improvement in the apparatus for combining multiple continuous running lengths of ends of undrawn multifilament yarn into a tow where the prior are combination was means to hold the ends, means to combine the ends, at least one means to linearly move the tow of combined ends, and means to collect the tow. The improvement comprises means to impart false twist to the tow of combined ends. Prior art apparatus was (a) a creel of yarn packages feeding yarn to (b) a guide means which combines the ends from the yarn packages into a single tow, (0) feed rollers such as driven roll with a pair of pressure rolls or a godet with separator rolls so that the yarn is held in driven contact with the driven roll are used to feed the yarn, and (d) collecting means. More than one feed roller can be used. The yarn is collected, for example, over a large guide roll to a piddler-nozzle into a tow can. It could also be wound onto a large beam, but a tow can and piddler-nozzle are conventional. The multiple ends of yarn could also be available from a multiple prime source such as spinnerette nozzles or from any kind of a yarn package such as a piddle can, a random wound package, precision wound package, a cone, a tube, a pirn, or a beam. The preferred apparatus which is the heart of this invention to impart the false twist consists basically of a hollow tube twist spindle, of sufficient inside diameter to permit passage of a desired number of yarn ends to form the tow, with two twist pins projecting through the tube adjacent to the tow ends. The tube is carried in bearings and equipped with a pulley and belt to impart rotary motion to the tube from any prime mover source such as an electrical motor. The hollow tube twist spindle rotates at a speed preferably between 250 and 750 rpm, typically about 400 rpm. However, the optimum speed will depend on the denier and type of yarn being processed and speed at which it is being taken up. Spindle speed should therefore be adjustable, for example, from 200 to 3,500 rpm. The tow can be composed of from about to about 2,000 ends of multifilament yarn having from about 3 to about 1,000 filaments per end. Each of the individual filaments in the end can have a denier from about 3 to about 50 and the tow can be taken up by a collection means at a speed of from about 500 to about 1,500 feet per minute, preferably about 800 to about 1,200 feet per minute. The twist spindle should be located between the creel or the source of the ends and the first feedroll. The preferred means to impart false twist is a rotating tube such as a twist spindle, i.e., the hollow tube described above. The preferred means to hold the ends to be combined into the tow is a creel with packages of yarn arranged in the creel. As can be seen from the above description of the hollow tube twist spindle, the means to impart false twist can be integral with the means to combine the ends into a tow. The process and apparatus of this invention solve the tight end problem at minimal initial cost. The rotation of the twist spindle applies twist to the yarn between spindle and the creel. As the yarn subsequently passes from the spindle to the first feed roll, the twist is removed. Thus, only false twist is applied.

The twist applied to the yarn as it leaves the creel has two beneficial effects: (1) Tight ends are broken out as soon as they occur, and before slack has a chance to develop in the remaining ends. (2) The twisting action wraps the broken end around the other ends smoothly and evenly thereby avoiding the problem of a loose end projecting from the tow.

These two effects wholly eliminate the subsequent processing problems described proviously. It should be noted that in addition to being much less expensive than the installation of tight end cutters, the use of the twist spindle has the advantage of trapping the broken end as described above.

DESCRIPTlON OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall means and method to combine multiple continuing running lengths of ends of undrawn multifilament yarn into a tow. Creel 1 contains yarn packages 2 which are fed to twist spindle 3 by first feed roller 4 and second feed roller 5 across large guide wheel 8 to piddle nozzle 6 into tow can 7. The individual ends 9 from yarn packages 2 in creel 1 are combined in the twist spindle 3 on fixed mounting 16 into a tow 10.

FIG. 2 is a cross-section view and shows details of hollow tube twist spindle 3. Yarn enters twist spindle 3 through flared opening 1 l. Twist pins 12 are fixed near the ends of twist spindle 3 so that ends 9 are twisted as they are combined into the tow in twist spindle 3. Twist spindle 3 is mounted on bearings 13 which in turn are fixed to fixed mounting l6. Twist tube is rotated by pulley 14 which is driven by belt 15 which in turn is driven by a motive source such as a motor not shown.

We claim:

1. In a method of combining multiple continuous running lengths of ends of undrawn multifilament yarn into a tow, the improvement comprising combining said ends by passing said ends through means to impart false twist to said combined ends and maintaining uniform lay by said twist breaking any tight end,

trapping broken loose ends by wrapping said loose ends about other continuous ends with said twist,

said ends of yarn being continuous multifilament yarn.

2. The method of claim 1 wherein said means to impart false twist is a rotating tube, said rotating tube containing at least one twist pin, said combined ends continuously passing through said tube.

3. A method of claim 2 wherein said rotating tube rotates at from about 200 to about 3,500 rpm.

4. The method of claim 2 wherein said tube rotates at from about 250 to about 750 rpm.

5. The method of claim 3 wherein said tow is composed of from about 50 to about 2,000 ends of multifilament yarn having from about 3 to about l,000 filaments per end, each of said filaments having a denier of from about 3 to about 50, and said tow travels at from about 500 to about 1,500 feet per minute.

age V UN TED STATES PATENT OFFICE QERTEFICATE 0F ECORECTON Patent No. 3, 855. 778 Dated December 24, 1974 Inventofls) Adolph John Brandi, Sr. and James Vincent Muthig It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Item [75] Inventor's name "Adolph John Brandi" should be --Adolph John Brandi, Sr..

Column 1, lines 51 and 52, the figure --2oshould be inserted after the dollar mark, "S".

Column 2, line 4, "are" should 'be -art-.

Column 2, line 11, after. "as" insert -a--.

s g ed and sealed this 11th day of March 1975.

{SEAL} Attest:

' I C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. In a method of combining multiple continuous running lengths of ends of undrawn multifilament yarn into a tow, the improvement comprising combining said ends by passing said ends through means to impart false twist to said combined ends and maintaining uniform lay by said twist breaking any tight end, trapping broken loose ends by wrapping said loose ends about other continuous ends with said twist, said ends of yarn being continuous multifilament yarn.
 2. The method of claim 1 wherein said means to impart false twist is a rotating tube, said rotating tube containing at least one twist pin, said combined ends continuously passing through said tube.
 3. A method of claim 2 wherein said rotating tube rotates at from about 200 to about 3,500 rpm.
 4. The method of claim 2 wherein said tube rotates at from about 250 to about 750 rpm.
 5. The method of claim 3 wherein said tow is composed of from about 50 to about 2,000 ends of multifilament yarn having from about 3 to about 1,000 filaments per end, each of said filaments having a denier of from about 3 to about 50, and said tow travels at from about 500 to about 1,500 feet per minute. 